Controllable pitch propeller



Oct. 22, 1968 NUTKU CQNTROLLABLE PITCH PROPELLER 4 Sheets-Sheet 1 Filed Aug. 15, 1967 INVENTOR.

BY I W 09m 9 Oct. 22, 1968 NUTKU CONTROLLABLE PITCH PROPELLER 4 Sheets-Sheet 2 Filed Aug. 15, 1967 INVENTOR. NU 7'.(/,

QM mm Oct. 22, 1968 A. NUTKU 3,406,759

CONTROLLABLE PITCH PROPELLER Filed Aug. 15, 1967 4 Sheets-Sheet 4.

INVENTOR. A 74 A/(/7Z BY Kin MW (mm, %441/ United States Patent 3,406,759 CONTROLLABLE PIT-CH PROPELLER Ata Nutku, Caddebostan, Iskele C. 1/ 3, Istanbul, Turkey Filed Aug. 15, 1967, Ser. No. 660,796 14 Claims. (Cl. 170-135.4)

ABSTRACT OF THE DISCLOSURE The invention provides a jet driven controllable pitch propeller comprising a hub having extending blade means, of split hydrofoil cross-section including a leading blade portion and laterally spaced tail vanes, said vanes defining discharge slot means on the trailing edge of the blade, a fluid duct extending lengthwise of the blade, located between the leading portion and said vanes, said vanes defining a discharge slot extending lengthwise of the blade in communication with said fluid duct, water inlet ports leading from the sides of the blade body into said duct, a venturi chamber located between said duct and said discharge slot, water inlet passages formed in opposite sides of the blade body and opening into'the venturi chamber, fins extending across said discharge slot and spaced therealong, a tubular blade stock on the inner end of the blade journaled on said hub, said hub having a closed chamber, operating mechanism operatively connected to the blade stock, rotary actuating means for said mechanism extending lengthwise through the hub, operating means externally supported relative to the hub and connected to said actuating means, and means for sup: plying jet fluid under pressure to the hub chamber and into the blade fluid duct.

This invention relates to a gas-hydraulic jet driven controllable pitch propeller, adapted for marine propulsion, pumps, water turbines, and other hydrodynamic application.

In the case of mechanically driven propellers, expensive and difficult to maintain, engines or motors are the driving media, which by their thermal and mechanical losses limit their quasi-propulsive efficiency, cause loss of deadweight capacity in ships, due to the extra weight of their engines, and by their use of normal types of propellers, problems, such as limitation of diameter, r.p.m., cavitation, etc., efficiency is curtailed, and in the cases of existing controllable pitch propeller propulsion systems, push-pull rod mechanisms require costly and complicated hydraulic control systems working under very high pressures. In attempts to drive ships by direct jet propulsion, low efficiency, emanating from high ratio of ship speed and slip stream velocity of the jets makes their adaptation objectionable and impractical.

The primary object of the present invention is the provision of a gas-hydraulic jet driven controllable pitch propeller, working on the ejector principle, whose use eliminates the need for a driving engine or motor, the said jet propeller being instead, driven by fluids such as gas, steam, air, or water, or a combination thereof, which can be supplied by a generating source on the associated vessel, the said fluid or mixture being jetted from nozzles at the trailing edge of the propeller.

Another object of the invention is the provision of a propeller of split hydrofoil cross-section, having venturi fluid jet nozzles in a fluid discharge slot in the trailing edges of the blades of the propeller, with water intake ports leading into the slot, the said fluid nozzles, having at their sides, water passages which open to a common discharge for the fluid and for water drawn through water passages and ports, by the stream of jetted fluid, whereby 3,406,759 Patented Oct. 22, 1968 there is obtained the benefit of a combined jet fluid and water stream, which produces the thrust for rotation of the propeller, together with the contribution of torque forces produced due to the flow of stream in the curved fluid duct, and also by the lift forces of nozzles due to their hydrofoil configuration additionally contributing to torque for rotation.

A further object of the invention is the provision of a propeller, whether jet fluid driven or otherwise, wherein the blades of the propeller are together rotatable for changes in pitch, and for reversing, by simple mechanical means, rotationally driven by small and inexpensive electric or hydraulic motors, mounted on the shaft flange of a boat, which serves both to change the blade pitch to the desired angle and to hold the blades in such adjustmerits.

In the drawings:

FIGURE 1 is a fragmentary transverse section, taken on the line 1-1 of FIGURE 2, parts being broken away and in section;

FIGURE 2 is a vertical longitudinal section, taken on the line 2-2 of FIGURE 1;

FIGURE 3 is a longitudinal section, taken on the line 3-3 of FIGURE 2;

FIGURE 4 is an enlarged vertical transverse section, taken on the line 4-4 of FIGURE 2;

FIGURE 5 is a section taken on the line 5-5 of FIG- URE 1;

FIGURE 6 is a view, like FIGURE 5, of an alternate form of propeller blade;

FIGURE 6a is a view, like FIGURES 5 and 6, showing another alternate form of propeller blade;

FIGURE 7 is an expanded schematic diagram, partly in vertical longitudinal section, illustrating drive and control means for the propeller, located in a ship;

FIGURE 8 is an enlarged vertical section, taken on the line 8-8 of FIGURE 7, showing the fluid jet nozzle and maneuvering gear, at the inner end of the screw shaft; and

FIGURE 9 is a fragmentary longitudinal section, taken on the line 9-9 of FIGURE 8.

Referring in detail to the drawings, and first to FIG- URES 1 to 5 thereof, the illustrated propeller 10 comprises an elongated cylindrical cross section, hollow hub 12, having a flat aft end wall 14, a rearwardly extending cone 16, the hub 12 merging, at its forward end, into a reduced diameter axial tubular extension 18, having a smooth axial bore 20.

Each of the propeller blades 106 comprises a preferably solid blade body 126 having a generally split hydrofoil cross-section, with one leading portion 127, and a pair of laterally spaced tail vanes 129, defining a discharge slot 131 and 158, as illustrated in FIGURES 5 and 6, which provides a tapered and rounded leading edge 128, and two trailing edges 130. The blade body 126 is hydrodynamically centered relative to and preferably integral with the root end of the related blade stock 68. Given the above-described cross-section, the blade body 126 has a cambered back 132 and a face 134, the major portion of which may be straight or cambered, and is preferably formed into a streamlined configuration.

As shown in FIGURE 1, the leading edge 128- of the blade body 126 curves radially outwardly so that its tip 136 is located behind its blade stock 68. The trailing edges of the blade body 126 may be straight or concavely curved.

The blade stock 68 has an axial bore 140, which is registered with the inner end of a jet fluid duct 142, which extends along the skew curve of the blade body, at the after-end of the leading blade portion 127, and has a leading wall 144 which is curved along the skew curve, with dents or steps 145 for water inlet ports leading from back of the blade into the duct 142. As shown in FIG- URE 5, the duct 142 is pear-shaped in cross-section, with its larger cross-section bounded by the wall 144. The duct 142 is tapered in cross section toward the blade tip 136.

The open smaller trailing end portion 147 of the duct 142 opens to a relatively narrow jet orifice 146, which provide forventuri discharge of jet fluid from the duct 142, into a substantially larger cross section water venturi chamber 148, which opens to the discharge slot 131 or 158, between the vanes 129, at the trailing edge of the blade body. The venturi chamber 148 has convex to straight side walls 150, which provide between them, at the after ends thereof, a V-shaped flaring discharge nozzle aperture 152, and at their forward ends, V-shaped water inlet passages 154. Further, the leading part of the blade body 126 containing the duct 142 terminates, at its trailing end, in converging walls 156, which are spaced from water passage walls 150, so as to provide water intake ports which are spaced along the major portion of the length of the leading blade portion of the blade body 126.

Extending between the vane wall portions 150 and 152, and spaced along the length of the chamber 148 are transverse fins 158, between which are defined combined water and jet fluid nozzles 160. The fins 158 have streamlined trailing edges 162 which are located on circles concentric with the axis of the hub 12 of the propeller, and rounded larger cross section leading edges 164. The backs 166 of the fins are convexly curved ,and their inner faces 168 are concavely curved, so that the fins have curved hydrofoil cross sections, with the leading edges of adjacent fins spaced closer together than their trailing edges.

In the case of the propeller blade 106a, shown in FIG- URE 6, an alternate form of blade body cross section of the blade body 126a, is embodied, the dimensions and proportions ofthe water passages and discharge chamber 148a being reduced and changed for increased venturi discharge of combined water and jet fluid, according to the nature of the jet fluid used.

FIGURE 6a shows another form of propeller blade 106b, involving further reductions in related cross sec tions.

In the hub 12 of the propeller, a center axial gearwheel 22 has a stub shaft 24 journalled, as indicated at 26, through the hub aft wall 14 and the cone l6, and a shaft 28 extending rearwardly from the gearwheel 22, is axially and spacedly in the bore 20 of the extension 18. The center gearwheel 22 is stabilized in place by a rear shoulder 28, bearing against the hub rear aft wall 14 and a forward shoulder 30, bearing against the transverse strut 32, extending across the interior of the hub 12. An antifriction bearing 34 is inset, as indicated at 36, in the front side of the strut and is traversed by the shaft 28.

The center gearwheel 22 is in mesh with, in this case, three equally circumferentially spaced outer or planetary gearwheels 38, having rear stub shafts 40 journalled, as indicated at 42, through the hub aft wall 14 and the cone 16. Threaded maneuvering shafts 44 extend forwardly from the outer gearwheels 38, and, at their forward ends, are supportably journalled, as indicated at 46, in the front wall 48 of a hub chamber 50, containing the gearwheels 22 and 38 and their shafts.

The bearing 34 is also inset, as indicated at 52, in the rear end wall 54 of a jet fluid pressure tube 56, which fits in the rear part of the bore 20 of the hub extension 18. Jet fiuid ports 58 are provided, at equally spaced intervals around the side wall 60 of the tube 5, in which are suitably secured, radial tubular collars 62, having reduced outer ends 64. The outer ends 64 are sealingly seated in tapered seats 66, in the inner ends of tubular propeller blade stocks 68.

The propellerblade stocks 68 are cylindrical in cross section, and are journalled through accommodating'openings 70 in the sides of the hub 12.- Th? stocks 68 have inner bearing collars 72, at their inner ends, which bear against flat sides of the hub chamber 50, and external bearing collars 76, which are rotatably supported, relative to the hub 12, by means of bearings 78, engaged in recesses and 82, provided in the collars 76 and the exterior of the hub.

As shown in FIGURES 1, 2 and 3, each of the inner bearing collars 72 are provided, at the forward sides of the blade stocks 68, with radial slots 84, in which are engaged tubular bearings 86, which have inner ends 88, extending inwardly from the collars 72. Follower blocks are engaged with the inner ends 88, have stubs 92 journalled'in the bearings 86, and at right angles to the stubs 92, the blocks are formed with threaded bores 94, in which, the threaded maneuvering shafts 44 are threaded.

At its inner end, the jet fluid tube 56 is slidably sleeved, in a slip joint, over a reduced diameter rear end portion 96 of a rotatable pitch control tubular shaft '98, which is suitably journalled in the hub extension 18, and has adjacent to the rear end portion 96, a diametrical web 100, in which the forward end of the center shaft 28 is splined, as indicated at 102. The forward end of the shaft 28 is capped by a tear drop streamliner 104. With this arrangement, rotation of the tube 98, in either direction, by suitable means hereinafter exemplified, produces rotation of the threaded maneuvering shafts 44, and thereby rotation of the propeller blade stocks 68, for effecting and maintaining pitch adjustments, and astern orientation of propeller blade bodies 106, of which the stocks 68 are component parts.

FIGURE 7 shows an illustrative installation of a propeller 10 for propelling a ship B, wherein the stern of the ship has installed therethrough a cylindrical outer casing 108, through which extends a tubular stationary shaft 110, which reaches rearwardly beyond the stern, and has, on its forward end, an annular flange 112, upon which are mounted small electric or hydraulic motors 114. The motors 114 have driving pinion worm gears 117, which are in mesh with the worm wheel 118-, which is fixed on the rear end of the tubular control shaft 98. Rotation of control shaft 98, for changing pitch of the blades 106, of the propeller 10, in either direction, is obtained by operating the motors 114.

For supplying jet fluid under pressure to the interior of the tubular control shaft 98, whether steam or some other gaseous fluid, the same is supplied from a source, such as a boiler 120, installed in the ship B, the fluid being ejected from an axial jet nozzle 124, through the tubular shaft 98, the nozzle 124 being incorporated in an ejector venturi nozzl which has water inlets 127 for a mixed jet of gas-water under pressure. Anti-friction bearings 129 and 139, between the jet nozzle body and the worm wheel 118, and between the hollow shaft 110, and the tubular control shaft 98, are arranged, as shown in FIGURE 9.

While the invention has been described with respect to gas hydraulic jet driven controllable pitch propellers, it will be obvious that the same described structure may be used with minor or no changes when driven by a jet or jet plasma however derived and propelled.

What is claimed is:.

1. A gas-hydraulic jet driven controllable pitch propeller comprising a hub having blade means extending therefrom, said blade means comprising a. blade body of a split hydrofoil cross section comprising a leading blade portion and laterally spaced tail vanes, said vanes defining discharge slot means on the trailing edge of th blade body, fluid duct means extending lengthwise of the blade body, said duct means being located between the leading blade portion and said vanes, said vanes defining therebetween said discharge slot means extending lengthwise thereof, said fluid duct means being in communication with said discharge slot means, said duct means comprising water inlet ports leading from the sides of the blade body into the said duct, a venturi chamber located between said duct means and said discharge slot, water inlet passages formed in the opposite sides of the blade body and opening into said venturi chamber, jet means comprising fins extending across said discharge slot means and spaced therealong, said blade body having a tubular blade stock on its inner end journalled on said hub, said hub being formed with a closed chamber, operating mechanism operatively connected to the blade stock, rotary actuating means for said mechanism extending lengthwise through the hub, operating means externally supported relative to the hub and connected to said actuating means, and means for supplying jet fluid under pressure to the hub chamber and into the propeller blade body fluid duct.

2. A propeller of the character described comprising a hub having a propeller blade body extending therefrom, said blade body being of split hydrofoil cross section and having a solid leading blade portion and spaced trailing vanes, a lengthwise extending jet fluid duct located between the leading body portion and said vanes, said body being formed with water passage means located between the leading body portion and the vanes, said vanes defining venturi discharge jet nozzle means therebetween, said water passage means and said jet fluid duct opening to said nozzle means, said blade body having a tubular stock having a bore opening to said jet fluid duct, and means for supplying jet fluid under pressure into the bore of the blade stock.

3. A propeller according to claim 2, wherein said blade means are formed, on their faces and backs thereof, adjacent to the trailing edge of the leading portion of the blade means, with water intake passage means communicating with venturi discharge nozzle means, said discharge nozzle means comprising a lengthwise extending venturi discharge chamber formed between the cambered inner faces of the tail vanes, opening full length to the trailing edges of the blade means, and formed between lengthwise spaced fins of hydrofoil cross section extending across said chamber, beginning with the opening of the fluid jet nozzle of the fluid duct at the trailing edge of the leading blade portion, said fluid duct leading from blade stock to blade tip with a skew having venturi jet nozzles at its trailing edge and a dented leading wall.

4. A propeller according to claim 2, wherein said blade means are formed, on the faces and backs thereof, adjacent to the trailing edge of the leading portion of the blade means and the noses of the tail vanes, with water intake passage means communicating with venturi discharge nozzle means, said discharge nozzle means comprising a lengthwise extending venturi discharge chamber formed between the cambered inner faces of the tail vanes, opening full length to the trailing edges of the blade means, and formed between lengthwise spaced fins of hydrofoil cross section extending across said chamber, beginning with the opening of the fluid jet nozzle of the fluid duct, at the trailing edge of the leading blade portion, said fluid duct leading from blade stock to blade tip with a skew, having venturi jet nozzles at its trailing edge and a dented leading wall, said fluid duct leading wall accommodating at its dents, water intake ports leading from water intake slits opened at the back of the blade means.

5. A gas-hydraulic jet driven controllable pitch propeller according to claim 1, wherein said blade means comprises at least two circumferentially spaced blade bodies, a center gearwheel journalled in said chamber and connected to said actuating means, planetary gearwheels journalled in said chamber and meshed with the center gearwheel and individually associated with the blade bodies, said planetary gearwheels having threaded shafts, said blade stocks having lateral collars formed with radial slots, follower blocks slidable in said slots, said follower blocks being threaded to run on the threaded shafts.

6. A gas-hydraulic jet driven controllable pitch propeller according to claim 1, wherein said blade means comprises at least two circumferentially spaced blade bodies a center gearwheel journalled in said chamber and connected to said actuating means, planetary gearwheels having threaded maneuvering shafts, said blade stocks having lateral collars formed with radial slots, follower blocks being threaded to run on the threaded maneuvering shafts, said follower blocks having stubs journalled in said slots.

7. A gas-hydraulic jet driven controllable pitch propeller according to claim 1, wherein said blade means comprises at least two circumferentially spaced blade bodies, a center gearwheel journalled in said chamber and connected to said actuating means, planetary gearwheels having threaded maneuvering shafts, said blade stock having lateral collars formed with radial slots, the follower blocks being threaded to run on the threaded maneuvering shafts, said follower blocks having stubs journalled in said slots, said actuating means comprising a tubular control shaft running inside the screw shaft of the ship, said tubular control shaft serving also as jet fluid pipe, and having on its ship-side end a worm wheel which is actuated by worm gears arranged on the shafts of the maneuvering motors mounted on the flange of said screw shaft.

8. A propulsion system comprising a propeller having a hub, means supporting the hub for rotation, said hub having a tubular extension extending axially therefrom, at least one propeller blade mounted on and extending from said hub, said blade having a body and a tubular stock journaled on the hub, said stock being formed with a bore communicating with the interior of said tubular extension, control means having mechanism within said hub and operatively connected to the blade stock for rotating the blade and changing the pitch of the blade in opposite directions, said control means comprising a rotary member extending through said tubular extension, rotating means operatively connected to said member, said blade body comprising a leading portion and laterally spaced trailing vanes, the spacing of the vanes defining a jet fluid discharge slot extending lengthwise of the blade body, said blade body being formed with duct means extending lengthwise of the body and communicating at its inner end with the bore of the blade stock, said duct being located between the leading portion of the blade body and said vanes, said duct being formed to provide a venturi slot spaced from and directed to discharge jet fluid to said discharge slot, water passage means spaced lengthwise of the blade body and opening to the opposite sides of the blade body, said water passage means leading into said discharge slot at opposite sides of said venturi slot, and means for supplying jet fluid under pressure through the hub to the bore of the propeller blade stock.

9. A propulsion system according to claim 8, wherein said fins extend across said discharge slot between said vanes, said fins being spaced from each other lengthwise of the discharge slot and defining jet therebetween.

10. A propulsion system according to claim 8, wherein said blade duct is curved relative to the axis of the blade stock radially outwardly and toward said discharge slot, said duct being tapered in cross-section radially outwardly from the blade stock.

11. A propulsion system according to claim 10, wherein said fins have convex outer surfaces and concave inner surfaces.

12. A propulsion system according to claim 8, wherein the facing surfaces of said vanes are convex to provide venturi passage of jet fluid through the discharge slot.

13. A propulsion system according to claim 8, wherein said water passage means are angled inwardly from the sides of the blade body toward said discharge slot.

14. A propulsion system according to claim 13, wherein said venturi slot and the cross-section of the blade body between said water passage means being narrower than said discharge slot.

(References on following page) 8 References Cited 423,590 2/1911 France. 1,188,483 3/1959 France. UNITED STATES PATENTS 11,668 1898 Great Britain. 3,253,660 5/1966 Maker 170160.48 X 5 1 037 9/194 Great Britain FOREIGN PATENTS 5 443,022 12/ 1948 Italy.

505,082 8/1954 Canada.

EVERE'ITE A. POWELL, JR., Primary Examiner. 

